20742657 has 8 divisors (see below), whose sum is σ = 29784384. Its totient is φ = 12764688.

The previous prime is 20742653. The next prime is 20742677. The reversal of 20742657 is 75624702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20742657 - 2² = 20742653 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20742653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 265893 + ... + 265970.

It is an arithmetic number, because the mean of its divisors is an integer number (3723048).

Almost surely, 2^20742657 is an apocalyptic number.

It is an amenable number.

20742657 is a deficient number, since it is larger than the sum of its proper divisors (9041727).

20742657 is a wasteful number, since it uses less digits than its factorization.

20742657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531879.

The product of its (nonzero) digits is 23520, while the sum is 33.

The square root of 20742657 is about 4554.4107192918. The cubic root of 20742657 is about 274.7608146148.

The spelling of 20742657 in words is "twenty million, seven hundred forty-two thousand, six hundred fifty-seven".